Themes are the fundamental and often universal ideas explored in a literary work.

The Unreliable Nature of the Truth 

Throughout the book, characters wrestle with whether what they think they know is really true as they navigate an upended world. Hannah and Bailey’s efforts to establish, or reestablish, the truth about Owen drive the plot. They want to ascertain the literal facts about him. More importantly, they need to confirm that the Owen they thought they knew—the good person, devoted father, and husband—was not an illusion. As they try to find their way to these truths, Tobias shares an Einstein quote with them: “So far as the theories of mathematics are about reality, they are not certain; so far as they are certain, they are not about reality.” This quote suggests that nobody can ever really know anything. The novel ultimately does not endorse this view, even if it does depict knowledge as more complex and messier than the characters initially assume.  

Ultimately, Hannah and Bailey learn to unpack multiple meanings and hidden truths from the information they have. Hannah suspects that the lies Owen told out of necessity retain a kernel of truth in them. This realization helps them uncover facts that finally prove Owen’s innocence. Ironically, the knowledge they gain while in Austin vindicates Hannah’s and Bailey’s view of Owen. The Owen they know may not exist legally, but he is nonetheless who they believed him to be. With this paradox, the novel suggests that people can still ultimately know fundamental or basic truths, provided they embrace a sufficiently flexible definition of what it means to know something.  

The Essence of Identity 

Hannah and Bailey each grapple with a crisis of self after learning about Owen’s false identity. To the extent that Hannah’s sense of identity stems from her perception of her marriage, Owen’s lies threaten her self-concept as well as her view of him. She particularly struggles to understand how she could have misread someone so thoroughly, worrying that it indicates that her judgment is poor. Hannah, however, has an identity separate from her husband. This is indicated by the fact that she does not take his name when they marry and that she has a successful career that brings her deep satisfaction. No matter how special her relationship with Owen is to her, she knows, through lived experience, that she can and does exist separately from him and their relationship.  

Bailey’s struggles, on the other hand, are more significant. Not yet an adult and without a mother, her sense of self is connected with her father. Bailey experiences Owen’s lies about her birthdate, her real name, and her mother’s identity as a terrible betrayal. Unlike Hannah, Bailey has no lived experience without Owen, and even more devastatingly for her sense of self, this lived experience is revealed to be built on deceit. Bailey’s crisis stems from the apparent destruction of the very roots of her identity. She desperately wants answers about who she is while also dreading what this information might reveal. Hannah ultimately chooses to sacrifice her marriage to ensure that Bailey can remain Bailey. This decision saves Bailey from losing her identity in witness protection, while also letting her develop ties, albeit distant, with her mother’s family.  

 The Connection of Family 

Hannah and Bailey experience how family ties can be both wounding and rewarding. Hannah worries she does not know how to be part of a family due to her childhood. Her parents’ distant attitude toward her culminated in her abandonment by her mother, though she ultimately had a happy upbringing with her beloved grandfather. Hannah sees Bailey as a fellow motherless girl, but their attempts to connect derail over misunderstandings and miscommunication. Bailey loves her father, the only parent she has ever known, and initially perceives Hannah as an interloper in their family. Although the absence of parents causes them much pain, the two motherless daughters eventually bond. Their time in Texas teaches both of them that Hannah can be a good and trustworthy maternal figure to Bailey. The final words of the novel, when Bailey calls Hannah “Mom,” demonstrate that Hannah is unquestionably Bailey’s parent now.  

Nicholas possesses a far more limited view of what constitutes family. He values the family he formed with his late wife and the literal kinship he has with his children and grandchildren. He tolerates Owen as a necessary evil for his daughter’s sake rather than as a true member of the family, even before their falling-out. He also bitterly resents Owen for taking Bailey away. Still, family ties drive the truce Hannah reaches with Nicholas. Hannah correctly guesses that Nicholas will make a deal for Bailey’s sake, and the arrangement includes a resumption of connection between Bailey,her grandfather, and her Uncle Charlie.